Add stream scheduling functions. Originally provided by Robin Seggelmann.
Add stream scheduling functions. Originally provided by
Robin Seggelmann.

ossy-szeged/sctp-refimpl,ossy-szeged/sctp-refimpl,ossy-szeged/sctp-refimpl,ossy-szeged/sctp-refimpl,ossy-szeged/sctp-refimpl,ossy-szeged/sctp-refimpl,ossy-szeged/sctp-refimpl,ossy-szeged/sctp-refimpl,ossy-szeged/sctp-refimpl